From: "J. Bruce Fields" Subject: Re: [PATCH 0/8] nfsd4: keep the client from expiring while in use by nfs41 compounds Date: Fri, 7 May 2010 18:38:36 -0400 Message-ID: <20100507223836.GO19142@fieldses.org> References: <4BE0A1AE.4040905@panasas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: NFS list To: Benny Halevy Return-path: Received: from fieldses.org ([174.143.236.118]:53781 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751504Ab0EGWig (ORCPT ); Fri, 7 May 2010 18:38:36 -0400 In-Reply-To: <4BE0A1AE.4040905@panasas.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, May 05, 2010 at 01:37:34AM +0300, Benny Halevy wrote: > Bruce, > > The following patchset changes the scope of the sessionid spin lock > to cover both sessions and the client lru list and it introduces a > new reference count on the client that's manipulated under that new > client lock (not requiring the state mutex). > > It's tested to pass connectathon tests as well as explicit session destroy > and implicit client expiry when the client is blown away. > However, I haven't tested the gist of this patchset which is to get > the client to perform a long enough compound during which it might time out... Yeah, I'm not sure how to test that. Create a temporary patch introducign a "delay X seconds" compound op, then teach pynfs to send those timed to coincide with client-reboot exchangeid's or the end of a client lease? So if I understand the intention of these patches right: behavior in the case of something explicitly destroys a client (e.g. client-rebooting exchangeid) is to partially destroy the client, but allow any concurrent compound to attempt to continue processing with the near-dead client? > [PATCH 1/8] nfsd4: rename sessionid_lock to client_lock > [PATCH 2/8] nfsd4: fold release_session into expire_client > [PATCH 3/8] nfsd4: use list_move in move_to_confirmed > [PATCH 4/8] nfsd4: extend the client_lock to cover cl_lru > [PATCH 5/8] nfsd4: refactor expire_client > [PATCH 6/8] nfsd4: introduce nfs4_client.cl_refcount > [PATCH 7/8] nfsd4: keep a reference count on client while in use > > [PATCH 8/8] nfsd41: cstate->session can NULL in nfsd4_destroy_session > I think this was introduced in: 26c0c75 nfsd4: fix unlikely race in session replay case > though I'm not sure how it ever worked correctly... Me neither. I've got a similar patch in my tree. --b.